In recent times, there has been increasing concern with regards to the effects of environmental tobacco smoke on the health of non-smokers. These concerns have resulted in restrictions of smoking in many public places in the U.S. R.J. Reynolds Tobacco Co. has recently developed a "New Cigarette" which by heating rather than burning tobacco produces emissions with substantially reduced smoke components. The environments generated by these new cigarettes apparently contain much lower concentrations of combustion and pyrolysis products and therefore may have reduced adverse effects on non-smokers as compared to tobacco burning cigarettes. Project 2 of this study will examine smokers after 12 week periods of smoking the "new cigarette" and standard cigarettes, alternatively. Project 4 will be identical to Project 2, with the addition of bronchoalveolar lavages (BAL) during screening and at weeks 12 and 24.